Refrigerant controlling apparatus



Jan. 12, 1932. J, F. HOFFMAN u 1,840,954 v RERIG'ERANT CONTROLLING APPARTUS y Filed Jan. 4, 1929 2 Sheets-Sheet l :1: 4/ y lNvENToR VB\;/0/1/7 Hoff/27a .W

ATTORNEY Jan. 12, i932. v .1. F. HOFFMAN 1,840,954

REFRIGERANT CONTROLLING APIARATUS l Filed Jan. 4. 1929 2 Sheets-Sheet 2 Y mvE Ton Joh/7 Hoff/nali BY ATTORNEY I Patented Jan. 1932 UNITED STATES PATENT ori-lcs JOHN F. HOFEHIAN',l 0F KAHA, NEBRASKA, ASSIGNOR T0 BAKER ICE MACHINE CO. INC., OF NEBRASKA, A OORPORATION 0F NEBRASKA.

BEFRIGEBANT CONTROLLING APPARATUS Application led January 4, 1929. Serial No. 330,184.

My invention relates to refrigerating systems and more particularly to apparatus in which a volatile liquid is expanded by reduction in pressure in an evaporator such as a coil to produce the refrigerating effect, the

r flash gases that may accidentally be admitted into the supply'line of the system toward an evaporator.

In some uses, for example when a l1qu1d such as ice cream 1s to be cooled, 1t 1s desirable to flood the cooling surface in order to effect the most efficient operation by transfer ofheat from a liquid to a liquid through the cooling surface. In such use sudden or excessive pressures may develop, particularly ywhen the`l exhaust end of the evaporator is closed, as in one stage of operating ice creaml apparatus, and thus subject the apangerous strain. o

Further ob'ects ofthe invention therefore are to provi e for exhausting a charge of refrigerant confined in an evaporator, and to assure automatic relief pf excess pressures. In accomplishing these and other objects of the invention, I have provided improved A details of structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is aperspective view of refrigerating apparatus including sup ly and return lines shown fragmentarily, an my improved safety device connected into the system.

Fig. 2A is a central vertical section of a valve for controllil throughthe supply e, a tube forming part of a thermostatic. control element being shown fragmentarily. Fig. 3 is a side elevation partly in central section of an evaporator and my control device connected thereto.

Fi 4 isa cross section of cooperating cylindncal trap members on the line H, 3, illustrating the position of athermostatic the ow of refrigerant loop in the chamber formed by the two members. l

Referring in detail to the drawings:

1 designates generally an evaporator supported on a pedestal 2 and comprising a cylindrical container 3 and a cylindrical jacket ,4

. spaced from the container to form an annular Vaporizing zone or chamber 5, such as employed for freezing ice cream, the zone corresponding to the interior of a refrigerating coil, and the specific structure representing4 apparatus with which the invention is particularly designed to be associated.

A pipe 6 leads from a source of refrigerant such as a compressor, not shown, and a valve 7 illustrated in detail in Fig. 2 and later described is mounted on the pipe 6 for controlling iiow of refrigerant toward the evaporator lthrough a supply line 8 connected to the valve and communicating at 9 with the chamber 5.

A return 10 leading back toward the compressor is connected as presently described to the chamber 5 whereby the circuit is provided for passage of refrigerant through the annular chamber to exchange heat with the contents of the' cylinder 3.

The above generally vdescribed structure is such as may commonly be found in systems of this character. l

I preferably connect the supply line 8 to the chamber 5 at arelatively low point as indicated in Figs. 1 and 3 and connectI the return at a high elevation to the chamber whereby refrigerant may flow in liquid state through the supply line into the chamber and normally4 substantially iood the same, the refrigerant being evaporated therein and passing thence lin Vapor state through the duction of ice cream.

' My invention includes an auxilia reservoir 12 comprising preferably a c hndrcal tank-like surge trap inserted in t e supply line 8 and preferably having an inlet 14 a# its lower end into which the supply pipe/isv connected and an outlet 13 opposite the inlet, I further preferably provide an enlarged portion 15 of lthe supply line for conducting the 'fluid from the outlet of thel reservoir 12 to the evaporator chamber.

Inserted in the return on the opposite side Y of the value 11 from the evaporator is an overflow trap 16 comprising a cylindrical casing having a greater diameter 'than the reservoir 12 and mounted over the same to form a partly annular chamber 17, the lower end 18 of the overflow trap beine inbent and secured to the outer surface of t e reservoir in spaced relation with the bottom thereof as clearly shown in Fig. 3.

The'upper end of the overflow trap ex- I tends upwardly beyond the reservoir 12, and

`is closed by a removable cover 19. The outlet 20 from the overflow trap tothe return is preferably locatedy at a point above the upper end'of the reservoir, while the inlet from the return to the 'trap is located adjacent the lower end thereof at 21, whereby fluid passing from the evaporator enters the lower end of the overflow trap into contact with a portion of the reservoir and rises'in the overflow trap toward Ithe outlet 20 thereof for affecting interchange of heat between the fluids in the two members as later described.

A thermostat tube 22 extends into the overflow trap adjacent the outlet 2O and preferably includes a circularly bent portion 23 over which the rising fluid will pass on its way to the outlet 20, the tube being extended lthrough the wall of the trap and connected at 24 with the controlvalve 6, the tube being adapted to contain a temperature responsive fluid whereby changes of temperature in the fluid in the overflow trap may cause expan.

sion and contraction of fluid in the tube and influence theval've 6, as later described.

The reservoir 12 has a closed lower end 25 and its open upper end 26 is provided with a sliding valve closure 27 having openings 28 closed by the wall of the reservoir when the valve is seated and ada ted for passage of fluid when the valve lis li ted under the influence of pressure in the reservoir. The valve is retained on its seat and adjusted to respond to predetermined pressure values by a spring `29 mounted between retaining members 30 l and 31 bearing respectively against the valve and a stem 32 screw-threadedly mounted in an opening 33in the cover 19 of the overflow trap. The stem is suitably packed to prevent escape of gases from the chamber 17.

The supply control valver'l' is described in detail in myv co-pending application Serial No. 299,393, and comprises a body 34 having a chamberv 35 in its upper end, an annular recess 36 in its lower end forming a boss 37, and caps 38 and 39 having recesses 40 and 41 and binding diaphragms 42 and 43 to the margins of the body recesses.

F luid under pressure passes through au inlet 44 and channel 45 to the recess 36, displacing t'he diaphragm 43 against the regulating influence of 'a spring 46 in the cap 39 andmovingth'rough a port' 47 into the central chamber, and thence through a channel 48 tothe chamber 35 and to the outlet 49.

Flow through channel 48 is controlled by pi'essure of fluid in the cap recess 40 and tube 22 influenced by temperature in the overflow trap 16, and operating throughdiaphragin 42 on a fluted stem 50 in the channel 48 against a ball valve 51.

Fluid may be admitted to the cap 38 and thermostat tube 22 through a channel 52 in the body and cap, and the intake may be further controlled by back pressure in the evaporator side of the supply line by admitting fluid to the recess 41 of cap 39 through a channel 53, the portions -of the channels 52 and 53 in the respective caps and the body com municating through suitable perforations in the respective diaphragms.

In operating apparatusequipped with control eleinents as described, for example when employed for freezing ice cream, the outlet valve in theretui'n is normally open, and refrigerantl will pass through the supply line to the evaporator in liquid state, and from the evaporator in vapor state to the casing or overflow trap, leaving the trap in a slightly superheated condition.-

The supply of refrigerant will be controlled responsively to changes in temperature of the departing vapor, through the thermostatic element including the tube coil and tube connected to the supply valve.

The relatively large trap will prevent es' cape of refrigerant in excessive quantities from the evaporator, should a slop over occur, and the in a dry state.

When the contents of the container have been sufliciently cooled, the cooling action mayfbestopped and a heating effect produced, by closing the outlet valve in the return, whereby pressure in they annular evaporator chamber is increased, with generation of heat, to warm the contents slightly and cause it to swell to bring about the desired overrun and produce a fluffy appearance and texture in the ice cream.

Pressure in the evaporator may however rise to a possibly dangerous value, and in such event the pressure will be relieved through the reservoir or surge trap, and through the pressure-responsive valve on the reservoir through which uid may move into the larger enclosing overow trap.

gas will pass from the trap v.

Steam -may be passed into the container zation of the refrigerant will be relieved through the elements mentioned.

The reservoir and casing above described further serve for exchange of heat between 5 the contents thereof, for example, fiash gas' moving-through the supply control valve to the reservoir, will pass upwardl to the top thereof, the reservoir wall con ucting heat from the gas to the fluid in the overflow trap or casing,.the gas passing into the casing through the 'valve of the reservoir where it will be condensed by direct contact and mixture with the cold gas'in the casing.

What I claim and desire to secure by Letters Patent is 1. In combination with refrigerating apparatus including a fluid supply line, an evaporator, anda return line, a surge trap Acommunicating with the evaporator and having its lower end connected into the supply line and a casing connected into the return line and extending over the upper portion of the surge trap for exchange of heat between fiuids contained by the surge trap and the casing.

2. In combination with refrigerating apparatus including a supply line, a'n evaporator, and a return line, a surge trap connected into the supply line and in permanent communication with the evaporator, a valve on the, trap normally closing one end of the same responsive to excessive pressure therein, and a casing interposed in the return line adjacent the trap and adapted to receive iluid delivered through the valve.

3. In combination with'refrigerating apparatus of the character described including an evaporating chamber, a supply line and a return line, a surge chamber member communicating with the sup ly line, and a casing communicating with t e return line and mounted on said surge chamber member in spaced relation therewithy for interchange of heat between fluid admitted to the sur e chamber from the su ply line and fluid a mitted to the casing om the return line.

4. In combination with a circuit for fluid under pressure including a supply line and a return line, a normally closed relief valve operable by pressure in the su ply line, and an overflow trap connected to t e return line and having communication through said relief valve with the supply line uponoperation of said valve for exchanging pressure values between the lines. l A 5. In combination with a circuit for fluid under pressure-including a supply line,- an expansion chamber, and a return line, a normally closed pressure relief valve responsive to pressure in the supply line, a casing connected tothe return li-ne surrounding said relief valve for affording communication between said casing and the supply linev through said relief valve, and means responsiveto changes in temperature in the casing for controlling flow of iiuid through the supply line.

6. In combination with refrigerating apparatus comprising a iuid circuit including a supply line, a return line, and a valve in the return line, a surge trap connected to the suppl line and provided with a normally close pressure in the supply7 trap interposed in ti communication with the suppl said relief valve is open for' re ief of pressure in the supply line into said sur 7. In a refrigerating system inclu ing an evaporating chamber and means for circulating a refrigerant including a supply line, a surge chamber member provided with a port and having a volume 'substantially equal to that of the evaporating chamber and in permanent communication therewith, and a pressure-actuated valve normally closing said line, and an overflow e return line. having port for relieving excess pressure in the surge chamber.

8, In a refri eratin system of the character describe inclu ing an evaporating chamber, a supply line, a return line, and a valve in the return line for suspending liow of refrigerant from the evaporating chamber, a casing interposed in the return line on the opposite side of said valve from said chamber, and means including a normally closed ressure-actuated valve communicating witl'l the supply line for relievin excess pressure in the evaporating cham er reversey through said valve into said casing.

9. n a pressure relief device for refrigerating apparatus including an evaporator, supply and return lines connected to the evaporator, and a manual control valve in the return line, a reservoir connected into the supply line and in permanently unobstructed communication with the evaporator, a pressure responsive valve onthe reservoir, an overflow trap connected into the return line on the opposite side of said control valve from the evaporator and adapted to receive fluid from the reservoir through the pressure responsive valve, and means including an ad'usted screw mounted in said overflow trap or adjusting the reservoir valve.

, 10. A pressure relief device for refrigerating apparatus including an evaporator, a supply line connected to theevaporator, a return line connected to the evaporator and having a cut-off valve, com rising a surge trap of capacity substantial y equal to the capacity of the evaporator connected into the supply line in ermanently unobstructed communication wit the evaporator, and hav- .ing a pressure responsive valve at oneend,

and an overflow trap connected into the return line on the opposite side of said eut-olf valve from the evaporator and comprising a cylindrical body extending over a portion of the surge tra and having a lower end sealingly secure to the surge trap and an line whenA e trap.-

pressure relief valve responsive to I iio upper end spaced from the valved end of the trap. v t

11. In combination with refrigerating apparatus of the character described including an evaporating chamber, a supply line, a return line and a supply control valve in the supply line, a surge chambermember communicating with thev supply line, a casing communicating with the return line and mounted on said surge chamber member in spaced relation therewith, and means including a Huid-containing tube in said casing for Controlling the supply line valve responsively to changes of temperature in the casing.

l2. n refrigerating apparatus including supply and return lines and an evaporator, a surge trap having a lower end connected te the supply line and an upper endy provided with a valve responsive to pressure in the trap, a conduit leading from the lower end of the surge trap to the lower side of the evaporator, a pipe leading rom'the upper side of the evaporator having an outlet end spaced below the inlet end of the return line and provided with a manually operable valve, land a easingsurrounding the upper end of the surge trap to receive fluid passing from the trap through said valve thereon, and having a lower end portion engaged with said trap and communicating with said pipe and an upper portion communicating' with the inlet end of the return line.

13. In combination with refrigerating apparatus including a iiuid supply line, an evaporator and a return line, a surge trap constantly communicating with the evaporator and having its lower end connected into the supply line and a casin connected into the return line and extending` over the upper portion of the surge trap for exchange of heat between fluids contained by the surge trap and the casing.

In testimony whereof I affix my signature.

JOHN F. HOFFMAN. 

